Digitized microimmunoassays with nuclear antigens for multiplex quantification of human specific IgE to β-lactam antibiotics

Abstract Microanalytical systems have huge potential for prognosis and diagnosis of diseases where the quantification of biomarkers is the critical factor. Immunoglobulin E (IgE)-associated allergy is the most common immune disorder and reliable multiplex quantification of specific IgE antibodies is of key importance for in vitro allergy diagnosis. Here, we report an unprecedented highly sensitive multiplex colorimetric microanalytical system for reliable quantification of s-lactam-specific IgE. The biosensor microsystem includes a regular digital versatile surface where nuclear antigens are immobilized in microarray format to determine simultaneously specific IgEs to amoxicillin, penicillin G, piperacillin and aztreonam, using a hacked disc drive as the optoelectrical sensor. The analytical microsystem was successfully tested in a cohort of 101 human serum samples, showing a limit of detection of 0.06 IU/mL (144 pg IgE/mL), a clinical sensitivity of 42.3 % for amoxicillin, and an excellent specificity (100 %). The analytical performances were good as compared and validated with both in vivo and in vitro reference clinical immunofluorescence assay, settling a good correlation between the techniques. The compact microanalytical system can be easily implemented in primary care laboratory settings without the need for any additional instrumentation, facilitating massive drug allergy screening and delabeling campaigns to better define drug sensitization profiles.